Galaxies
The
Nature
Of Universe
In The
Ancient's
Point
Of View
The Origin Of
Matter And
It's Spread
In Universe
Universe
contains 100 million galaxies, and every galaxy contains 100 million
stars, first of all we must know what the galaxy is and isn't. A galaxy is
a great collection of stars attached together by the force of gravity, and
it's considered as the building unit of universe, as universe consists of
galaxies. The smallest galaxy contains one million star and the biggest
one contains 300 000 million star, every galaxy has a center, some of them
have arms. The stars that are found in the center of any galaxy are always super giant
or giant red stars, but the stars of the arms of any galaxy are young blue stars.
This section includes the following topics:
Elliptical
galaxies:
They're very old galaxies as
their stars are very old from giant red and RR-Lyrae (old stars) and
Cepheid and this kind of galaxies hasn’t arms and its symbol is “E”.
Spiral
galaxies:
:It is another kind which has center and long arms, red stars are always
found in the center while the arms is from young blue stars its symbol of
is (Sa).
Two Spiral Galaxies
Barred
galaxies:
It likes spiral ones but its center is not a nucleus but along bar,
the stars of the arms is younger than those of the center
Irregular
galaxies:
It hasn’t a certain shape and it doesn’t rotate it contains a
lot of young and old stars
Lenticular
galaxies:
And it’s an intermediate link between elliptical and spiral
galaxies and it has a nucleus, but hasn’t any clear arms.
Dwarf
galaxies:
And it is from the kind “E” but it’s smaller and spherical and
it’s stars is very old, it is always affected by the bigger galaxies.
Dwarf galaxy
CD
galaxies:
It’s like dwarf ones but it’s much bigger (it’s radius is 165
000 light year while dwarf only 3500), and it’s more active.
Whirlpool
galaxies:
And it’s similar to spiral galaxies, but it’s nucleus or center
is not clear, but it has big opened arms like M51 galaxy (canes venactici)
constellation.
Seyfert
galaxies:
It was discovered by “Carl Seyfert”, like spiral or barred
galaxies but they are more active, perhaps because of the presence of a
huge black holes in them, has a nucleus and it’s surrounded by very
powerful magnetic field, long columns of plasma always comes out of it.
N-type
galaxies:
They were
discovered in 1958, and they is similar to sayfert galaxies, but
they're more shiny and their radio-activity is much greater than sayfert,
center of these galaxies is smaller, and n-type galaxies are considered a
very rich radioactive source its symbol is SA.
Sombrero
hat galaxies:
And they were named by this name because of the similarity between
the Sombrero hat and them, around the center there is an unusual bulge,
M-104 is approximately the only example to this galaxies in the Virgo
constellation.
Mar
karian galaxies:
And they were discovered by Mararin and they’re dwarf, elliptical
from “E” type but the center consists of a very hot young stars and
ionized gases.
Bl-Lacerta
bodies (objects):
It is
a very powerful radioactive source some of them like Elliptical ones but
without nucleus and the others like spiral without any other radiation,
and it’s very old, far and mysterious.
Quasi
steller object:
And
it’s known by Quasars, the first quasar was discovered in 1963 and
it’s name is 3C-273, it’s the first or the nearest quasar (just 200
million light years away from earth as all quasars are very far, irregular
and mysterious), although it is small (not bigger than 100 star systems)
but it’s very shiny, perhaps there’s a black hole inside each quasar.
